Hair and pectinate chaetae
in the dorsal bundles of fore- and mid-body; ventral chaetae
with slightly longer upper tooth anteriorly but with equal tooth in postclitellar segments.
include dorsal fascicle of 3-4 geniculate bilimbate chaetae
, five modified spines alternating with spear-shaped companion chaetae
and fascicle of short unilimbate neurochaetae; younger modified spines generally straight with sharp points, older spines worn, with slight concavity (Fig.
TURBELLARIA: Dugesia tigrina - 9; OLIGOCHAETA: Naididae: Nais bretscheri - 2, Nais communis - 1, Nais pardalis - 12, Nais simplex - 6, Nais variabilis - 8, Pristina foreli - 2, Pristina osborni - 1, Tubificidae: Limnodrilus maumeensis - 1, Limnodrilus udekemianus - 2, immature tubificids without capilliform chaetae
- 12, Enchytraeidae - 7, unidentified oligochaete - 1; Hirudinea: Placobdella ornata - 1; HYDRACARINA - 4; EPHEMEROPTERA: Caenis sp.
IV with globular apex; basolateral ms above the 2nd proximal row of chaetae
Juveniles removed from tubes 1-2 days after metamorphosis were about 350 [micro]m in length, with six chaetigers (the anterior three bearing capillary chaetae
and the posterior three hooded hooks: Fig.
Two tentacular segments are fused bearing two pairs of tentacular cirri, and chaetae
present along the second pair.
It is considerably larger there: 12-18 mm long, consisting of (35)50-58 segments, and with (1-3)4-8 chaetae
, measuring 70-110 [micro]m, per bundle (Timm 1999).
Thus, many features were regarded as very variable including antennal size and articulation, the type of pectinate chaetae
, and the number of teeth in the maxillae.
Burrowing by polydorids was initially believed to be carried out mechanically by the chaetae
, in particular the modified chaetae
of the filth chaetiger (Blake & Evans 1973).
Groups Vea, Vem and Vep with 4, 3 and 4 chaetae
There has been some debate as to whether polychaete boring is carried out by chemical means (Haigler, 1969) or mechanically using modified chaetae
(Hannerz, 1956), After reviewing the literature and conducting experiments, Van der Pers (1978) established that a combination of both mechanisms is important for boring in polychaetes.
disjuncta) lacks a tentacular crown but uncini and chaetae
resemble those found in Sabellidae.